Tape casting is a technique, which can be used, for example, for the manufacture of flat, large area ceramic components. Tape cast products are found in a wide variety of industries, such as microelectronics, photovoltaic solar applications, laminated composites, rapid prototyping, and the like. The tapes can be cast with thicknesses ranging from a few microns to a few hundred microns. For most applications, it is crucial that the control of green tape thickness is precise, and that these thickness values are consistently reproducible.
Current tape casting techniques involve the dispersion of a powdered material (i.e., comprising the final phase) into a solvent, and the addition of dispersants and other casting ingredients to form a homogeneous slurry. Ball milling is typically used to form a homogeneous suspension. The slurry is cast into tapes by, for example, casting the slurry onto a moving carrier surface, such as mylar or cellophane, and spreading the slurry to a controlled thickness with the edge of a blade. Casting is followed by drying of the tape to evaporate solvent, and final sintering of the tape at elevated temperatures (e.g., at temperatures of about 650° C. to over 1500° C.) to form either thick film type or bulk form ceramic components.
Nanostructured components play increasingly more important roles in many areas such as magnetic materials, catalysts, fuel cells, filters, electrodes for batteries, chemical sensors, and gas separators. Available techniques for fabrication of nanostructured components include chemical routes such as spin or dip coating, spray pyrolysis, and chemical vapor deposition; and physical routes such as severe plastic deformation, physical vapor deposition, and thermal plasma spray. However, existing tape casting methods are not suitable for production of nanostructured components because of the high temperatures required for sintering of the green tape. There thus remains a need for improved tape casting methods, particularly those that allow the production of nanostructured tapes.